Which of these would be the best recipe for preparing a solution buffered at pH 10? The Ka values for benzoic acid and phenol are 6.3 × 10–5 and 1.3 × 10–10 respectively.
A. use benzoic acid and add a little strong acid
B. use benzoic acid and add a little strong base
C. use phenol and add a little strong acid
D. use phenol and add a little strong base